/Engine/Source/Runtime/AssetRegistry/Public/AssetRegistry/IAssetRegistry.h
bool DoesPackageExistOnDisk ( [FName](API\Runtime\Core\UObject\FName) PackageName, [FString](API\Runtime\Core\Containers\FString) * OutCorrectCasePackageName, [FString](API\Runtime\Core\Containers\FString) * OutExtension ) const